Abstract

An efficient self-consistent approach combining the nonequilibrium Green’s function formalism with density functional theory is developed to calculate electron transport properties of molecular devices with quasi-one-dimensional (1D) electrodes. Two problems associated with the low dimensionality of the 1D electrodes, i.e., the nonequilibrium state and the uncertain boundary conditions for the electrostatic potential, are circumvented by introducing the reflectionless boundary conditions at the electrode-contact interfaces and the zero electric field boundary conditions at the electrode-molecule interfaces. Three prototypical systems, respectively, an ideal ballistic conductor, a high resistance tunnel junction, and a molecular device, are investigated to illustrate the accuracy and efficiency of our approach.

Received 06 August 2007Accepted 05 October 2007Published online 21 November 2007

Acknowledgments:

This project was supported by the National Natural Science Foundation of China (Grant Nos. 90406014, 90206048, and 60671022) and the MOST of China (No. 2007CB936204). S.S. thanks Science Foundation of Ireland (Grant No. SFI02/IN1/I175) for financial support.